The stain on your underwear as a result of sharting, sometimes permeating to the outer layers of your clothing. Usually accompanied by a putrid odour. Biohazardous.
I thought I just farted, then I checked my underwear and saw a huge krassenstein.
I could smell the krassenstein as he took off his trousers.
As I walked into the room, the dog ran straight to me and nuzzled my krassenstein
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)